1. Field of the Invention
This invention relates, in general, to load carrying systems for hikers, and in particular, to an improved flexible pack frame having a lateral, pivoting joint and/or resilient flex joints connecting adjacent parts of the pack frame and allowing the pack frame to support the load to be carried in close proximity to the wearer's body while closely following the movement of the wearer's hips and shoulders. A pack bag having a pleated portion which allows the upper and lower portions of the bag to follow the respective movements of the hips and shoulders of a hiker in an improved manner is also disclosed.
2. Description of the Prior Art
Stuides of human anatomy have been shown that the when a person is walking, the hips, supported by the legs, pivot about the lower portion of the spine, and that the spinal column itself resembles a flexible cable which joins the lower torso to the upper torso. The arms and shoulders, in turn, pivot about the upper end of the spinal column. While the lower torso is best suited for supporting a load that is carried on the body, this burden is most efficiently carried when it is as close as possible to the upper body and distributed about the upper body in such a way that its weight can be transferred, to a substantial degree, to the waist and lower torso area.
Flexible pack frames are known, such as shown in my prior U.S. Pat. Nos. 3,563,431 and 3,733,017, as well as in U.S. Pat. No. 3,734,366.
Also known are hip belt and shoulder strap systems for backpacks, such as shown in U.S. Pat. Nos. 2,104,486, 3,347,429, 3,536,237, 3,831,827 and 3,840,162, which have attempted to provide for the transfer of a pack load from the shoulders to the hips of the wearer and to control the movement of the pack frame in response to the movement of the hips and shoulders of a hiker.
None of the above prior patents, although occasionally disclosing significant advances in the art, have disclosed pack frames able to follow both the vertical and rotational movements of the hips and shoulders of the human body while walking to the degree possible with the pack frame of the present invention. Neither have these patents disclosed pack frames which allow the load carried on the frame to be closely distributed about the upper body of the wearer both when the hiker is walking on level ground and when the hiker is either climbing or descending a steep grade.
The prior art additionally includes early patents disclosing apparatus for assisting in carrying equipment on the human torso, which apparatus includes hinges or pivot points such as U.S. Pat. Nos. 1,296,619, 1,448,918, 1,589,463 and 1,637,635. The apparatus disclosed in these patents not only functions differently from the pack frame system of the present invention, but also is not directed to the solution of the problem solved by the present invention, namely, the provision of a flexible pack for hikers which allows a load to be carried such that the pack moves with the body of the hiker in a manner responsive to the relative vertical, lateral and rotational movements of the hips and shoulders of the hiker such that the load is maintained in close proximity to the torso of the hiker at all times.
Pack frames formed of interconnected tubular members are also known, such as shown in U.S. Pat. Nos. 3,860,157, 3,912,138, 3,219,243 and 4,018,370. These patents disclose structures for joining tubular members having a different function and design than the joiner member of the present invention. U.S. Pat. Nos. 3,000,656 and 3,851,980 also disclose tubular joiner members, in general, which also differ in structure and design from the joiner members of the present invention. Copies of all of the above-listed patents were submitted to the Patent Office at the time of the filing of this application.